He crashed his car while attempting to escape and was dragged from the vehicle, placed against a tree and shot in the head, the union said.

"There is great concern there has been more activity in the last week in terms of evicting farmers and looting homes" across the country, said Jenni Williams.

White farmers have been accused of providing transport and logistical backing for the opposition Movement for Democratic Change, the biggest threat to Mugabe's rule.

Several independent observer groups have condemned the March 9-11 elections as deeply flawed and designed to ensure Mugabe's re-election.

South African President Thabo Mbeki and Nigeria's Olusegun Obasanjo were to meet Mugabe to discuss Zimbabwe's future after two years of widespread violence blamed mainly on ruling party militants.

Mbeki was also expected to meet opposition candidate Morgan Tsvangirai.

Mbeki, Obasanjo and Australian Prime Minister John Howard will meet in London tomorrow to discuss possible Commonwealth action against Zimbabwe.

The Commonwealth observer mission said the election did not adequately allow voters to freely express their choice. Industrialised Commonwealth members have called for Zimbabwe's expulsion for abusing the group's charter on democratic rights.

Since Mugabe was declared the winner of the elections last week, white farmers have reported an upsurge in violence in rural areas.

Mugabe led the nation to independence from Britain in 1980 and faced little dissent until recent years, when the nation's economy collapsed and political violence erupted.

Mugabe won the polls with a disputed 56% of votes to Tsvangirai's 42%.